环氧透明质酸改性脱细胞猪真皮基质的亲水保湿性研究

湿性愈合理论证明了创面修复过程中,保持伤口湿润环境至关重要。为了改善脱细胞猪真皮基质（pADM）敷料的亲水保湿性能,采用环氧化透明质酸（EHA）与pADM交联改性,将高亲水保湿的透明质酸（HA）分子引入到pADM中,制备得到环氧透明质酸改性脱细胞猪真皮基质（EHA-pADM）。采用傅里叶红外光谱仪、原子力显微镜、收缩温度测定仪、差示扫描量热仪等对不同用量EHA改性得到的EHA-pADM进行分析。结果表明：EHA-pADM热稳定性随着EHA用量的增加而升高,产生了交联效应,且EHA-pADM仍然保持着pADM原有的二级结构、三股螺旋结构、横纹结构等微观结构特征。EHA-pADM的表面接触角随着EHA用量的增加而降低,其吸湿率和保水率与EHA用量基本正相关。吸湿动力学分析显示,EHA-pADM对水的吸附量随着EHA用量的增加而提高,吸附特征符合二级动力学方程,吸附过程属于多分子层吸附。可见,HA分子的引入,提高了pADM的表面亲水性能,增加了其保水“锁水”能力。当EHA-pADM用作敷料时,有望成为一种新型的亲水保湿型医用敷料。     

季铵盐改性脱细胞猪真皮基质的研究

采用不同用量(1%、5%、10%)的十二烷基三甲基氯化铵(DTAC)浸渍脱细胞猪真皮基质(pADM),测定了改性后pADM的接触角、吸湿率、溶胀率、毛细管吸水率以及对大肠杆菌、金黄色葡萄球菌的抑菌性能。结果显示:通过DTAC处理后的pADM,接触角随DTAC用量的增大而减小,吸湿率、溶胀率与毛细管吸水率随DTAC用量的增加呈现先升高后减小的趋势。随着DTAC用量的增大,抑菌圈直径也增大,抑菌性能增强。     

原花青素交联脱细胞猪真皮基质的研究

采用浓度0.7%(w/w)的天然原花青素(OPC)对脱细胞猪真皮基质(pADM)进行改性,研究了交联材料(OPC-pADM)的收缩温度、机械强度、亲水性、降解性和急性毒性。研究结果显示:经OPC交联后,pADM的收缩温度和变性温度明显升高,证明OPC与pADM产生了明显交联作用;交联后材料抗张强度升高,耐降解能力增强;吸水率、保水率的升高和接触角的降低,说明交联材料的亲水性能增加。动物实验表明,OPC-pADM无明显急性毒性。     

纳米材料改性脱细胞猪真皮基质的研究

将纳米SiO2、纳米TiO2及纳米银的溶液与脱细胞猪真皮基质(porcine acellular dermal matrix,pADM)复合,考察改性前后材料的表面微观结构、收缩温度、抗张强度、透水汽性、孔隙率和抗菌性能。研究结果表明:纳米材料能以纳米粒子状态较好地分布于pADM内,随着纳米SiO2、纳米TiO2用量的增大,改性后的pADM收缩温度提高,抗张强度提高,孔隙率增大,透水汽性提高,对大肠杆菌和金黄色葡萄球菌具有良好的抗菌效果;纳米银改性后的pADM收缩温度降低,抗张强度增大,孔隙率减小,透水汽性略有减小,对大肠杆菌和金黄色葡萄球菌具有优良的抗菌效果。     

槲皮素改性脱细胞猪真皮基质的研究

采用不同浓度的槲皮素(QCT)交联改性脱细胞猪真皮基质(pADM),并对改性后的脱细胞猪真皮基质(QCT-pADM)材料进行傅里叶红外光谱、DSC、TG、表面形貌和耐降解性能等表征。结果显示,槲皮素的引入不会改变pADM中胶原的三股螺旋结构;改性后脱细胞猪真皮基质材料纤维编织更为紧实,热稳定性能得到提升,耐酶解性能和亲水性能大幅提高。     

第一代氨基化胶原纤维的制备及其对染料的吸附性能研究

以乙二胺(EDA)为原料、三聚氰氯(CNC)为交联剂对制备的猪皮胶原纤维(CF)进行氨基化改性,得到以胶原纤维为基质的第一代氨基化胶原纤维(ACF-1)吸附材料;用水杨醛法测定了改性前后胶原纤维中氨基含量的变化,并用扫描电镜(SEM)和红外光谱(FTIR)分别对改性前后胶原纤维的组织形态及分子结构进行表征;将制备的吸附材料用于染料吸附试验,通过单因素法分别考察了吸附剂用量、染料质量浓度、温度、pH和吸附时间对染料吸附的影响.     

挤压改性稻壳吸湿性能、动力学与热力学研究

为有效利用稻壳(rice husk,RH),通过双螺杆挤压技术处理RH制备挤压改性稻壳(extru-sion-modified rice husk,ERH).对比恒温恒湿箱(温度25℃、相对湿度80％)中ERH与RH于不同时间的吸湿性能,研究吸湿动力学模型.在相对湿度80％时,测得吸湿剂在不同温度下的吸湿量,得到吸湿标...     

木质纤维素负载金属氧化物对水中砷吸附性能研究

以木质纤维素为基础材料,通过负载Al、Fe-Ce、Ce-Mn金属氧化物对纤维素进行改性,制备重金属离子吸附剂。实验研究了改性吸附剂对水中砷离子的吸附行为,考察砷初始浓度、pH、吸附时间等因素对吸附效果的影响。结果表明:Fe-Ce、Ce-Mn双金属氧化物改性的吸附剂在pH=4时,Al氧化物改性吸附剂在pH=7时,对砷的吸附效果最佳;三种金属氧化物改性吸附剂均在10 min内可达到吸附平衡;动力学研究表明:三种改性吸附剂对砷的吸附过程均符合准二级动力学模型,均以化学吸附为主;通过对等温吸附模型的拟合表明,三种改性吸附剂均符合Langmuir等温吸附模型,说明其以单分子层吸附为主,最大吸附容量分别为Al 27.1 mg·g~(-1)、Fe-Ce 33.75 mg·g~(-1)、Ce-Mn 31.19 mg·g~(-1)。     

CuO/聚丙烯/乙烯-辛烯共聚物复合熔喷非织造材料的制备及其吸油性能

为高效经济地处理油品泄漏引起的污染问题,利用聚丙烯(PP)与乙烯-辛烯共聚物(POE)共混后制备复合熔喷非织造材料,然后在其表面负载纳米氧化铜(CuO)进行疏水改性.对改性前后非织造材料的形貌、结构、水接触角、吸油和力学性能等进行测试.结果 表明:负载纳米CuO后,CuO/PP/POE复合熔喷非织造材料的结晶度下降,熔...     

柠檬酸改性核桃壳对水中Cr(Ⅲ)的吸附

采用柠檬酸热化学法制备改性核桃壳(CAWS),用于吸附模拟废水中低浓度的Cr(Ⅲ),并采用SEM和FT-IR对改性前后、吸附前后的核桃壳进行表征。结果显示:改性后的核桃壳孔隙结构增多,有利于Cr(Ⅲ)的吸附。改性最佳条件为:柠檬酸∶核桃壳质量比为9∶10,时间3h,温度130℃。在初始Cr(Ⅲ)溶液质量浓度为20mg/L,初始pH值为5,温度为25℃,吸附剂投加量为20g/L,吸附时间为125min的条件下,CAWS对Cr(Ⅲ)的去除率为88. 55%,高于相同条件下未改性核桃壳对Cr(Ⅲ)的去除率78. 17%。吸附过程符合二级动力学方程,相关系数较高(R~2 0. 99); Freundlich和Langmuir等温吸附模型都可用于描述吸附过程(R~20. 95)。     

羧甲基纤维素吸水性纱布的制备及其吸湿性动力学分析

对纤维进行羧甲基化处理,可将强亲水性的羧甲基引入纤维素分子结构中,使其吸收液体的能力显著提高。本文以普通棉纱布为原料,通过控制氯乙酸(MCA)的用量,制备了不同取代度(DS)的羧甲基纤维素(CMC)吸水性纱布,研究了DS值不同的CMC吸水性纱布的吸湿动力学。结果表明,CMC吸水性纱布具有较强的吸湿能力,当MCA用量与纤维素糖单元的摩尔比nMCA：nAGU=2:1时,DS值可达到43.10%,DS值越高,吸湿性越好。DS值为43.10%的样品在RH=81%时吸湿率可达18%左右,平衡吸湿量为182.39 mg/g。采用二级吸附动力学方程能够很好地描述其吸湿行为,相关系数达0.999以上,并且计算得到的平衡吸湿量与实验值接近。     

兔毛纤维的吸湿性能

对兔毛纤维的润湿性能和吸湿性能进行研究,测定兔毛纤维的接触角和在标准状态下的吸放湿特征曲线,并与羊绒纤维进行比较,根据特征曲线推导出兔毛纤维在标准状态下达到吸、放湿平衡过程中回潮率对于时间的回归方程以及吸、放湿速率方程。结果显示:未经洗涤的兔毛纤维具有良好的润湿性能,与羊绒纤维相当,但其吸湿能力稍低于羊绒纤维,初始吸湿速度与羊绒相近,放湿速度低于羊绒,达到吸、放湿平衡所用时间要长于羊绒纤维。     

Effect of the relative humidity of drying air during the resting period on the composition and appearance of dry-cured ham surface

This study evaluates the effect of three different relative humidities (RH) during the resting period on the composition of the external part of Semimembranosus muscle (2 mm thick) and the appearance of the surface of the dry-cured ham after resting and ageing. Forty-eight hams stored after salting for 40 days at 4±1 °C and three different RH (52±3, 78±3 and 85±3%) were studied. Half of the hams in each treatment were sampled after the resting period and the rest were aged for 8 additional months at the same temperature and RH. Storage of hams at 52% RH during resting produced a white appearance in some parts of the rind and increased the surface covered with oil drip. Hams stored at 78% showed a similar composition to those stored at 52%, except for the higher moisture content and lower Na/moisture ratio at the end of the resting period, and potassium content (on dry matter, dm) at the end of the process. At the end of resting no white rind was observed, and at the end of the process the surface covered with oil drip was slightly lower than at 52%. Storage of hams at 85% RH increased the surface pH, Na2HPO4.12H2O crystallisation, Mg (dm), Mg/moisture, K (dm) and NPN/NT at the end of the resting period, and increased the pH and Mg (dm), Mg/moisture, Na/moisture, K/moisture, the ash (dm) and ash/moisture contents and decreased the a_w and the surface covered with oil drip at the end of the process.     

重量法研究大豆水分吸附速率和有效扩散系数

在5种温度（10³5℃）、3个湿度（RH 65%、86%及100%）组合环境中,以称重法测定了初始低水分（4.33%⁵.85%）、正常水分（11.74%¹2.65%）、高水分（17.58%¹7.89%）两个大豆品种\     

环境湿度对常压等离子体处理拒水纤维效果的影响

针对常压等离子体处理过程中水分存在的问题,在空气相对湿度分别为5％、65％和95％时,对超高模量聚乙烯进行常压等离子体处理,测定处理前后纤维的静态接触角以及纤维与树脂间的层间剪切强度,采用原子力显微镜和X射线光电子能谱探测纤维表面的变化.结果表明,处理后纤维表面粗糙度、含氧基团和纤维与树脂间的层间剪切强度增加,静态接触...     

无氟自清洁功能型羊毛/羊绒混纺织物的研发

为提高羊毛/羊绒(60/40)织物自清洁能力,降低织物因清洗而造成毡缩变形等不良影响,采用常压等离子体对羊毛/羊绒混纺织物表面进行预处理,再使用微纳米级乙酰丙酮锆及聚二甲基硅氧烷自制无氟环保型毛织物拒水剂对织物进行静电喷雾疏水处理。通过分析织物等离子体处理前后静态接触角变化及红外测试结果,发现最佳等离子体处理参数以及对织物毡缩性能的影响。比较等离子体处理前后及等离子体预处理再进行疏水整理织物的外貌形态、静态接触角、透湿透气性、防紫外线性能差异。结果表明:羊毛/羊绒织物经等离子体预处理再进行静电喷涂具有优异的疏水性能,静态接触角提高至152°,达到超疏水临界值,织物透湿透气性仅分别降低2.98%、1.65%,毡缩性下降4.61%,此外,该方法辅助提高了织物14.14%的紫外线防护系数。     

疏水改性乳清分离蛋白-普鲁兰多糖复合气凝胶的制备及性能研究

目的:对易吸湿的蛋白/多糖类气凝胶进行疏水改性并对其性能进行评估。方法:对乳清分离蛋（whey protein isolate,WPI）-普鲁兰多糖（pullulan,PUL）复合气凝胶进行低温等离子体处理,使其羟基充分暴露后,使用硅烷偶联剂进行表面接枝处理,获得具有疏水性能的复合气凝胶,并研究其吸湿性、疏水疏油性、抗压性能、热失重、精油装载与缓释性能等。结果:甲基三甲氧基硅烷（methyltrimethoxysilane,MTMS）改性后复合气凝胶的平衡吸湿率为（9.67%±0.323%）,十八烷基三甲氧基硅烷（octadecyltrimethoxysilane,OTMS）改性后复合气凝胶平衡吸湿率为（9.34%±0.276%）,相比为改性前（11.41%±0.506%）均明显降低;改性前,复合气凝胶水接触角为（40.14°±2.16°）,油接触角为（28.07°±2.43°）;MTMS改性后水接触角为（82.10°±4.78°）,油接触角为（56.14°±3.25°）;OTMS改性后水接触角为（85.21°±4.61°）,油接触角为（74.63°±3.08°）;改性后疏水疏油性均有所提升,且OTMS改性处理效果更好。改性前复合气凝胶压缩模量（21.745±1.982）MPa,MTMS改性后（17.655±3.034）MPa,OTMS改性后（18.412±3.513）MPa。改性后抗压强度略有降低,但不影响正常使用。改性前复合气凝胶丁香精油的最大装载率为（254.26%±5.585%）,MTMS疏水改性后丁香精油最大装载率（241.57%±5.214%）,OTMS组则为（223.31%±4.436%）。丁香精油装载率有所下降但缓释性能均有所提升,且MTMS改性缓释效果更好。热稳定性方面均有所提升,且OTMS组热稳定性更好。结论:综上所述,硅烷接枝疏水改性处理可以显著提升复合气凝胶的疏水性并提高其亲油性。适用于油脂类活性物质的装载与缓释应用,拓宽了WPI-PUL复合气凝胶的应用领域。     

Effects of anticaking agents and storage conditions on the moisture sorption,caking, and flowability of deliquescent ingredients

Deliquescent highly soluble crystalline ingredients are prone to caking and dissolution when they are stored above a certain relative humidity (RH) but exhibit minimal moisture adsorption below this RH. Anticaking agents are added to improve the flowability of powders and to prevent or reduce caking. The objective of this study was to determine the effects of anticaking agents on the moisture sorption behavior, flowability, and caking characteristics of deliquescent ingredients and blends thereof. Single deliquescent food ingredients (sodium chloride, sucrose, fructose, and citric acid) and binary systems (sodium chloride blended with sucrose, fructose, or citric acid) were used as the host powders, and silicon dioxide, calcium silicate, and calcium stearate were the three anticaking agents studied. Moisture sorption isotherms were generated to investigate the water–solid interactions of the anticaking and host powders. Following controlled RH storage treatments, caking was assessed by the sieve test and flowability by avalanche power and avalanche angle measurements. Formulation had variable effects on deliquescence behavior and moisture sorption, while formulation, storage RH, length of storage, and RH cycling all significantly affected the physical stability of the powder blends. Calcium stearate was the most effective anticaking agent at reducing moisture sorption and delaying the onset of deliquescence, as well as maintaining the flowability properties of all powders tested. In particular, calcium stearate was able to substantially alter the moisture sorption behavior of blends of deliquescent ingredients, which are inherently more susceptible to the deleterious effects of moisture due to deliquescence lowering. The results are of great significance because they show that the effectiveness of an anticaking agent in preventing moisture-induced caking depends on the complexity of the host powders as well as on the interaction with environmental moisture. Thus, the type of anticaking agent added to a deliquescent ingredient must be tailored to the host powder to enhance product quality and stability.     

Hydrophobic recovery of atmospheric pressure plasma treated surfaces of Wood-Polymer Composites (WPC)

In this study, the behavior of atmospheric pressure plasma treated surfaces of Wood-Polymer Composites (WPC) was investigated as a function of time and environmental conditions. The surfaces of injection molded WPC based on polypropylene (PP) and polyethylene (PE) were treated by a dielectric barrier discharge (DBD) and subsequently aged under various conditions. The wettability as an indicator for change of the composite surface was assessed using water contact angle. In addition, a calculation for half-time of the contact angles was developed to predict the time span which is needed for recovery of hydrophobicity. The results showed a major influence of temperature and time, whereas the humidity only at storing conditions of 60?°C and 75% relative humidity showed a distinct effect on the activated surface. The effect of DBD treatment was stable for more than one week in the climates 20?°C and 0% RH and 20?°C and 65% RH.     

金属酚醛/两性离子聚合物涂层聚丙烯补片的制备及其抗蛋白吸附性能

为将亲水两性离子材料与惰性聚丙烯(PP)补片有效结合,降低蛋白质在补片表面的吸附,利用三价铁离子和单宁酸(TA)层层自组装的金属酚醛网络(MPN),介导聚羧酸甜菜碱甲基丙烯酸酯(PCBMA)固定在PP补片上,对该改性涂层补片的微观形貌、表面成分、接触角、表面电位、力学性能、抗蛋白吸附性能和细胞毒性进行表征与分析。结果表明:MPN可将PCBMA均匀固定在单丝表面,改变补片的表面化学组成;PCBMA-Fe/TA涂层将PP表面的水接触角降低至37°,表面电位由-55.7 mV提高到-5.14 mV;涂层不影响PP补片的力学性能,并为补片带来了显著的抗蛋白吸附效果;改性补片的相对细胞活力达到89%,表现出良好的生物相容性。研究结果有望为惰性医疗器械的抗污改性提供参考。